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(Adds new efficacy numbers for South Africa)
By Michael Erman
Feb 24 (Reuters) - Johnson & Johnson's one-dose
COVID-19 vaccine appeared safe and effective in trials, the U.S.
Food and Drug Administration said Wednesday, paving the way for
its approval for emergency use as soon as this week.
The vaccine was 66% effective at preventing moderate to
severe COVID-19 in a 44,000 person global trial, the FDA said in
documents ahead of a Friday meeting of independent experts who
will advise the agency on emergency authorization.
New data provided by J&J to the FDA showed the vaccine was
64% effective at stopping moderate to severe cases of COVID-19
after 28 days in thousands of trial participants in South Africa
where a worrying new variant has swept across the country.
Overall, the vaccine was 100% effective at stopping
hospitalization 28 days after vaccination, compared with 85% at
14 days, and there were no COVID-19 deaths among those who
received the shot rather than a placebo.
J&J also said the data suggested its vaccine cut down on
asymptomatic infections, which experts said was another sign
COVID-19 vaccines may indeed stop transmission of the disease.
"Most encouraging to me were the data in South Africa," said
Paul Offit, director of the Vaccine Education Center at the
Children's Hospital of Philadelphia and a member of the FDA
advisory committee that will make its recommendation on Friday.
"That you could still get protection against medically
attended illnesses - meaning hospitalization, ICU admission and
deaths from that vaccine against the South African strain, I
thought that was really encouraging."
While the FDA is not bound to follow the advice of its
experts, it approved both the Pfizer and Moderna
vaccines the day after the advisory committee met.
The United States, where COVID-19 has killed more than half
a million people, has been struggling to speed up its
vaccination program because of the limited supply of the
Pfizer-BioNTech and Moderna vaccines so far.
Worldwide, COVID-19 has infected 112 million people and
killed more than 2.5 million and governments are racing to get
their hands on any effective vaccines.
ASYMPTOMATIC TRANSMISSION CUT
J&J said this week that it expected to have 4 million shots
ready to go following an FDA green light and would ship 20
million doses by the end of March. It has promised the United
States 100 million doses by the end of June.
The vaccine is administered in a single dose and can be
stored in normal fridges, in contrast to the Pfizer and Moderna
shots which need two doses and must be kept in freezers.
The J&J vaccine is also considered essential in the global
vaccination effort due to its routine storage requirements and
is already being rolled out to 500,000 healthcare workers in
South Africa.
J&J said in documents submitted to the FDA that in a
preliminary analysis of its trial, it found 16 cases of
asymptomatic cases in the placebo group versus two in the
vaccine group, or an 88% efficacy rate.
While fighting asymptomatic infection was not the primary
goal of the trial, which studied the vaccine's ability to stop
moderate to severe COVID-19, the reduction of asymptomatic cases
implies the shot can also cut transmission of the disease.
"The data is consistent with the fact that these coronavirus
vaccines, including the J&J vaccine, do have an impact which is
significant on asymptomatic spread," said Amesh Adalja, a senior
scholar at the Johns Hopkins Center for Health Security.
However, he said some public health authorities may ask to
see more robust data before being persuaded.
The effectiveness of the one-dose vaccine varied over time.
In Brazil, where a similar variant to the one in South Africa is
circulating, the vaccine was 66% after 14 days, rising to 68% at
28 days. In the United States, the effectiveness fell from 74%
at 14 days to 72% two weeks later.
Overall, only two vaccine recipients developed COVID-19
severe enough to need medical intervention after 14 days and
that dropped to zero after 28 days.
J&J has said it sees rising immunity from its vaccine until
at least 28 days after injection. The drugmaker has said it
expects sustained - or even improved - protection over time.
SIDE EFFECTS
Three vaccine recipients had severe side effects in the
trial that were likely related to the vaccine, but the FDA said
its analysis did not raise any specific safety concerns that
would preclude issuance of an emergency use authorization.
The FDA said the most common reactions were injection site
pain at 48.6%, headache at 39%, fatigue at 38.2% and myalgia at
33.2%. Other side effects included a fever in 9% of participants
and a high fever in 0.2% of those who received the vaccine.
The regulator said one case of pericarditis, a heart
disease, may have been caused by the vaccine. It said cases of a
rare disorder, Guillain-Barre Syndrome, were unlikely to be
related to the shot though data was insufficient to determine
whether the vaccine had caused these side effects.
(Reporting by Manas Mishra in Bengaluru; Mike Erman, Caroline
Humer and Rebecca Spalding; Editing by Bernard Orr and David
Clarke)
